Household sinks usually have a U-shaped pipe that forms a trap, and have an elbow that follows the trap and a horizontal pipe section that follows the elbow. U.S. Pat. No. 3,168,104 shows an elbow that has a snake opening through which a “snake” can be inserted to clean out a stoppage such as a stoppage in the horizontal pipe section or in other pipe sections connected thereto. A plug closes the snake opening when a snake is not inserted. The elbow commonly has a nipple with internal threads, and the plug can be threaded into the nipple to close it. This results in one spot on the threads of the nipple being exposed to wear by the snake during use of the snake. The snake typically has a rough surface to help it loosen debris, and this rough surface can wear an end of the nipple threads and lead to leaking water. An elbow that provided the advantages of an elbow of the prior art but which avoided concentrated wear that could lead to water leakage, would be of value, especially where plastic pipes are used.